feat(marketing): say no card where the trial is actually claimed

Three places still carried the old promise. The register form, which is where
the CTA lands and where the trial is granted, said nothing about it at all, so
the landing page's claim had to be taken on faith across a page load. The
comparison profile summary still described the trial without mentioning the
card. And the CtaLink comment quoted a button label that no longer exists.

The hero and closing CTAs now read 'Open dashboard' for a signed-in visitor.
That button already pointed at /dashboard for them, and offering a free trial
to someone who is mid-subscription reads as a bug. The pricing card keeps the
short label because it sits directly under 'No credit card' and the card
narrows to about 230px at the md breakpoint, where the long label would wrap
out of a fixed-height button.

app/(auth)/register/page.tsx

@@ -1,6 +1,6 @@
 import { after } from 'next/server';
 import { readPageVisitor, recordVisitorEvent } from '@/lib/analytics/visitor';
-import { isInviteCodeRequired } from '@/lib/feature-flags';
+import { isInviteCodeRequired, isStripeFeatureEnabled } from '@/lib/feature-flags';
 import { getInvitationPreviewByToken } from '@/lib/invitations';
 import { isInvitationPreviewAllowed } from '@/lib/invitation-preview-limit';
 import RegisterPageClient from './register-page-client';
@@ -40,6 +40,7 @@ export default async function RegisterPage({ searchParams }: RegisterPageProps)
   return (
     <RegisterPageClient
       requireInviteCode={isInviteCodeRequired()}
+      trialOnSignup={isStripeFeatureEnabled()}
       googleEnabled={googleEnabled}
       githubEnabled={githubEnabled}
       invitation={invitation}

app/(auth)/register/register-page-client.tsx

@@ -21,6 +21,11 @@ export interface RegisterInvitation {
 
 interface RegisterPageClientProps {
   requireInviteCode: boolean;
+  /**
+   * Billing is on, so this account starts a free trial. False on a self-hosted
+   * instance, where there is nothing to trial and the promise would be a lie.
+   */
+  trialOnSignup?: boolean;
   googleEnabled: boolean;
   githubEnabled: boolean;
   invitation?: RegisterInvitation | null;
@@ -30,6 +35,7 @@ interface RegisterPageClientProps {
 
 export default function RegisterPageClient({
   requireInviteCode,
+  trialOnSignup = false,
   googleEnabled,
   githubEnabled,
   invitation = null,
@@ -156,6 +162,15 @@ export default function RegisterPageClient({
               Create Account
             </CardTitle>
             <CardDescription>Join OpenFrame to collaborate on video projects</CardDescription>
+            {/* The landing page CTA promises a trial and no card. Say it again here,
+                where the promise is actually kept, rather than making people take the
+                previous page's word for it. Invitees are joining someone else's
+                workspace, so the trial is not what brought them. */}
+            {trialOnSignup && !isInvitationFlow && (
+              <CardDescription>
+                Your 7-day free trial starts as soon as you create the account. No credit card.
+              </CardDescription>
+            )}
           </CardHeader>
           <CardContent>
             {/* OAuth Buttons */}